Roller and ram lift riveter



J. C. HANNA April 7, 1931.

ROLLER AND RAM LIFT RIVETER Filed April 26, 1950 Patented Apr., '1, 1931 4 UNITED STATES PATENT- oFFlcs JOHN C. HANNA, OF CHICAGO, ILLINOIS,v ASSIGNOR TO HANNA ENGINEERING WORKS, OF CHICAGO, ILLINOIS, A CORPORATION F yILLINOIS ROLLER AND RAM LIFT RIVETER V L Application led April 26,

This invention relates to improvements in riveting machines and principally to improvements in a riveting machine of the type including roller wedge mechanism for transmitting `the operating stroke from a fluid pressure device to a slidable ram. a

VI have previously pointed out the advantages of utilizing, instead of thecustomary lever or toggle mechanism between a slidable piston and a movable ram, cooperating cam surfaces formed by a wedge member whichis operated by the piston and a wedge block which is attached to the ram. By utilizing cam surfaces it is possible to obtain a variable working stroke and working pressure that will result in efficient riveting operating and cannot be carried out by the ordinary leverage means. The pressure has been transmitted between the relatively mov- 2o able cam surfaces through aA roller which is used to diminishV the friction; v The rollerv is designed to move in rolling contact with both yof the cam surfaces. During the cus- A tomary operation, the roller is retained'in ,25 its correct position and the working ram is case the roller is liable to be displaced. It-

is, therefore, .desirable that some means be `utilized to maintain the correct position of the roller relative to the movement of the` wedge member and further that some means be utilized vto effectuate the lreturn stroke of the ram should the force of the spring bey not sufficient to overcome the sticking which may occur.

40 It is, therefore, an object of thepresent invention to operate a ram of a riveter, or ma y chine for carrying out any similar operations, by roller wedge leverage mechanism whereby a desired variable working pressure may be secured and to cause the return stroke of the ram normally by a spring means, but Valso to provide means for positively starting the return stroke of the ram should it initially stick.

Y -Thus a particular feature the present 1930. Serial No. 447,495.

linvention resides in the provision of aV lever plate which is normally loosely pinned tothe wedge and to theram whereby,during the operating stroke, none of the Vworking pressure will be transmitted through the plate but, during the Vreturn stroke ofthe wedge,...

ward force on the ram which will be sufficient l to start the return stroke thereof. 1

Another object of the presentA invention consists in the provision of means for preventing displacement of the pressure transmitting roller during the relative movement between the parts. Normally the roller will be maintained in proper position bythe relative pressure between theoperating members but should the `cam surfaces become separated due to sticking of the ram, I have'proi preventing displacement of roller and of lifting the ram in lorder to start the return stroke. Y

Further objects and advantages of the present improvements will be more readily lapparent in connection with the following description describing thle vrembodiment shown inthe attached drawings inwhich- Figurelis la vertical sectional elevation through a portion of a riveting machine illustrating the improved featuresof construction.

tion of Figure l" illustrating the parts 'in a different position. 7

Figure 3 is va-vertical sectional elevation taken onthe plane'indicated by 3 3 in Figure 1. i A

In the drawings aY portion of aU-shaped riveting frame l0 is shown forming a guide 'for a vertically slidable ram 11, to the lower end of which a riveting die may be attached.

, 1 90 Figure 2 is a vertical elevation of a por- To the riveting frame 10 is attached a housing 12 which encloses the operating members. 13 is the main fluid cylinder and 14 is the return fluid cylinder. A piston 15 has secured thereto the main piston head 1G and return piston head 17. The action of the fluid pressure means is not important so far as the present invention is concerned. It is only necessary that means be provided to admit the fluid pressure to the main cylinder to cause the working stroke of the piston and that fluid pressure be admitted behind the piston head 17 to cause the return stroke of the piston.

At the end of the piston rod 15 within the housing 12 is mounted a. wedge member 18 which is designed with a flat upper surface 19 guided by a freely movable roller 2O which also bears against a guide plate 21 secured to the upper part of the housing 12. Projections 22 may be formed at the ends of the guide surfaces in order to prevent the roller 20 from over-running the guide surfaces. The lower side of the wedge 18 is formed with a double inclined cam surface 23 which corresponds to the cam surface 24 formed on wedge block 25, which is secured to the upper end of the ram 11 by thepin 26. Between the cam surfaces 23 and 24 is mounted a pressure transmitting roller 27. A spring 28 is enclosed within a portion of the riveting frame 10 and acts against the toe 29 of the wedge block 25.

The initial position of the wedge, roller and ram is illustrated in Figure 2 and it will be evident that upon the operating stroke of the wedge the roller will be caused to travel .relative `to the cam surfaces and due to the Y 28 until the parts finally come to the position shown in Figure 1. Upon the retractive stroke of the wedge, the ram shouldr be returned by the pressure of the spring 28 but it may happen that the riveting die will stick to the head of the completed rivet and prevent the upwardmovement of the ram by the force of the spring.

I show secured to the wedge 18 a plate 30 v which is held by the flat headed screw 31 and the bolt 32. A corresponding plate may be secured to the opposite side of the wedge. The plates 30 carry oppositely extended pins 33. Also from the wedge block 25, which is mounted onthe ram, extend pins 34. Lever plates 35 are mounted on the pins 33 and 34 and includev elongated slots 36 to receive the pins 34 and elongated curved slots 37 to receive the pins 33. Fixed fulcrum pins 38 extend inward from the housing 12 and are designed to be engaged by the heel portions 39 of the cam plates should the ram 11 stick. Thus if the wedge is retracted from the position shown in Figure 1 and the ram 11 does not start to move, the heel portions 39 of the lever plates will be brought to bear against the fulcrum pins 38 and through the slots 3G, will exert a force on the pins 34 in order to cause an upward movement of the ram 11. However, if the force of the spring 28 is suflicient, this action will not occur.

Another reason for using the slotted plates 35 is to provide means for loosely ournalling the roller 27 whereby it is substantially maintained in correct relation to the cam surfaces in spite of an abnormal separation thereof. Thus the roller 27 is provided with a pin 40 which extends therethrough and is loosely held by slotted openings 41 formed in the plates 35. It should be noted that the pins 33 which extend from the wedge member 18 travel in the curved slots 37. In the position shown in Figure 1, the pins 33 are in the upper ends of the slots 37 and during the retractive movement of the wedge, the plates 35 will be caused to turn to the position shown in Figure 2 in which the pins 33 are now at the lower ends of the slots 37.

During this movement, the roller 27 is given a defined path of movement due to its connection with the plates It should be further noted that during the working stroke,

due to the provision of the slotted openings for receiving the pins, none of the working pressure will be transmitted through the plates 35 and the only time that the plates 35 will receive any direct pressure is when the heel portions 39 of the plates are brought to bear against the fulcrum pins 38 in order to lift the ram.

Many modifications and changes may be resorted to in the practical embodiments of my improvements without departing from the spirit of my invention as expressed in the appended claims.

I claim:

1. In aV machine for performing riveting or like operations, a reciprocal plunger, means for imparting a working stroke to said plunger, said means including a wedge movable transversely to the axis of movement of said plunger, means resiliently opposing the working stroke of said plunger acting to return said plunger upon the retractive movement of said wedge and means for positively initiating the return stroke of said plunger should the force of the resilient means be insufflcient.

2. In a machine for performing riveting or like operations, a reciprocal plunger, means for imparting av working stroke to said plunger, said means including a wedge movable transversely to the axis of movement of said plunger, said wedge and said plunger including cooperating cam surfaces and a roller lll) 'figvgsaa o transmitting the pressure developed by said,

3. In a machine for performing riveting' or like operations, a fixed frame housing, a plunger adapted to be reciprocated relative to said housing, means for imparting a working stroke to said plunger, said means including a wedge movable tranvsersely to the axis of movement of said plunger, means resiliently opposing the working stroke of said plunger acting to return the plunger upon the retractive movement of said wedge and a slotted plate loosely connected to said wedge and said plunger arranged to be brought tof bear against the fixed housing to initiate the return stroke of said plunger should the force of the resilient means be insutlicient.

4. In a machine for performing riveting or like operations, a reciprocal working plunger, means for imparting a working stroke to said plunger, said means including a wedge movable transversely to the axis of said plunger, an intermediate roller member between said plunger and said wedge whereby the axis of said roller member will move in a curved` path during the relative movements of said wedge and said plunger, means for maintaining the proper relative positionof said roller comprising a loosely connected swivelled.

plate between said plunger andsaid wedge and said plate including a bearing for said roller member.

5. In a machine for performing riveting or like operations, a Xed frame housing, a plunger adapted to be reciprocated relative to said housing, means for imparting a working stroke to said plunger including a wedge movable transversely to the axis of movement of said plunger and a roller intermediate said wedge and said plunger, the axis of said roller being adapted to move in a curved path during the relative movements of said wedge and said plunger, means for resiliently opposing the working stroke of said plunger acting to cause the return stroke ofv saidV plunger upon the retractive movement of said wedge and to maintain the rolling contact between said wedgesaid plunger and said intermediate roller and means for positively initiating the return stroke of said plunger Y should the force of the resilient means be insufficient and for maintaining the proper` to said housing, means for imparting a working stroke to said plungerincluding a wedge movable transversely tothe'axis of movement of'said plunger and a roller intermediate said wedge and said plunger, the axis of said roller being adapted to move in a l curved path during the relative movements of said-wedge and'said plunger, means'for resilientfly opposing the working stroke of said plunger acting to cause the return stroke of said` plunger upon the retractive movement of? said wedge and to maintain the rolling cont-act betweeny said wedge, said plunger and Y said intermediate roller and mean-s for positively initiating the return stroke of said plunger should the force' of the resilient means be insuicient and'for maintaining the proper relative position of said roller during the return movements of said wedge and said plunger, said last-named means including a V'pairof swivelled plates loosely held to said `iii/"edge and said plunger by pin and slot connections, said plates including'bearing means 4 for said roller, and'said plates being so arranged that they will be fulcrumed about a fixed part of said frame should the plunger -remain stationary during the initial return movement of said wedge and thereby exert a return force to said plunger. y

' '7. In combination, ai fluid pressure actuated wedge member and a transversely movable ram, saidV wedgeV and said ram including oppositelydisposed and relatively movable cam surfaces, .a pressure vtransmitting roller normally 'in rolling contact with both of said cam surfaces, a plate pivoted to said ram and including a journal bearing for said roller and a pin and slot connection between said plate and said wedge whereby displacement of said'roller is prevented during the movement of said wedge and said ram.

8. In combination, a fluid pressure actuated wedge member and a transversely movable ram, said wedge and said ram including oppositely disposed and relatively movable cam surfaces, a pressure transmitting roller normally in rolling contact with both of said cam surfaces, spring means acting to oppose vthe working stroke of said ram caused by the movement of said wedge member and to return said ram upon the retractive movement of said wedge and means loosely connectingsaid wedge and said ram and operative to effectuate the initial return movement of said ram should the spring means be insufficient. Y 1

9. In combination, a fluid pressure actuated wedge member and a transversely movable ram, said wedge and said ram including oppositely disposed and relatively movable @am surfaces, a pressure transmitting roller normally in rolling contact with both of said cam surfaces, spring means acting to oppose the vworking stroke of said ram caused by the movement of said wedge member and to return said ram upon the retractive movement.

of said Wedge and means loosely connecting said Wedge and said ram and operative to eiiiectuate the initial return movement of said ram should the spring means be insucient, said loose connection means comprising a plate and pin and slot connections between said plate, said Wedge and said ram.

l0. In a machine for performing riveting or like operations, a slidable Working member, a transversely slidably movable Wedge operated by fluid pressure, said Wedge serving to eii'ectuate a Working stroke of said Working member, spring means for causing the return stroke of said Working member and means for positivelyT causing a return stroke of said Working member upon the retraction of said Wedge, said last-named means being actuated independently of said spring return means.

11. In combination, a vertically reciprocable Working member and a transversely reciprocable Wedge member operated by Huid pressure, a pressure transmitting roller between said members, pins extending from said Wedge and said Working member, a plate having elongated slots receiving said pins and a fixed fulcrum pin, said plates being designed upon the retractive movement of said Wedge to bear against and pivot about said fixed Jfulcrum pin in order to exert a lifting force on the Working member.

Signed at Chicago, Illinois, this 19th day of April, 1930.

JOHN C. HANNA. 

